Desiccating cartridge for firearm barrels

ABSTRACT

A cartridge-shaped container is provided which contains desiccating material, and which serves to prevent corrosion within the barrel of the firearm. The cartridge is insertable into the firing chamber of the firearm, and it contains molecular sieve adsorbent pellets which adsorb the moisture present in the bore of the barrel, so as to prevent rust and other forms of corrosion due to moisture within the barrel. An impervious plug is provided having a hollow end which fits over the end of the cartridge in friction fit with the cartridge to preserve the integrity of the molecular sieve pellets when the cartridge is not in use, and the other end of the plug is dimensioned to be insertable into the muzzle of the firearm to seal and enclose the bore of the barrel when the cartridge is in place in the firing chamber. The molecular sieve pellets within the cartridge may take the form of synthetically produced crystalline metal aluminol-silicates which have a strong affinity for water and certain other gases and liquids.

United States Patent [191 Hawkins [451 Nov. 26, 1974 DESICCATINGCARTRIDGE FOR FIREARM BARRELS [76] Inventor: Edward J. Hawkins, 13508 S.

Normandie Ave., Gardena, Calif. 90249 [22] Filed: Nov. 12, 1973 [21]Appl. No.: 414,897

[52] US. Cl 42/1 N [51] Int. Cl. F41c 27/08 [58] Field of Search 42/1 N[56] References Cited UNITED STATES PATENTS 2,465,163 3/1949 Lockwood42/1 N 2,557,277 6/1951 Gibson 42/1 N 2,594,778 4/1952 Hoard 42/1 N2,985,979 5/1961 Doyle, et a1. 42/1 N FOREIGN PATENTS OR APPLICATIONS596,261 12/1947 Great Britain 42/1 N 1,022,043 12/1952 France 42/1 NPrimary ExaminerBenjamin A. Borchelt Assistant Examiner-C. T. JordanAttorney, Agent, or FirmJessup & Beecher [5 7] ABSTRACT Acartridge-shaped container is provided which contains desiccatingmaterial, and which serves to prevent corrosion within the barrel of thefirearm. The cartridge is insertable into the firing chamber of thetirearm, and it contains molecular sieve adsorbent pellets which adsorbthe moisture present in the bore of the barrel, so as to prevent rustand other forms of corrosion due to moisture within the barrel. Animpervious plug is provided having a hollow end which fits over the endof the cartridge in friction fit with the cartridge to preserve theintegrity of the molecular sieve pellets when the cartridge is not inuse, and the other end of the plug is dimensioned to be insertable intothe muzzle of the firearm to seal and enclose the bore of the barrelwhen the cartridge is in place in the firing chamber. The molecularsieve pellets within the car tridge may take the form of syntheticallyproduced crystalline metal aluminol-silicates which have a strongaffinity for water and certain other gases and liquids.

5 Claims, 5 Drawing Figures BACKGROUND OF THE INVENTION The interiorsurface of the barrel of a firearm is usually protected against rust andcorrosion by the application of a film of gun oil or grease in order toprevent moisture-bearing air from coming into direct contact with thatsurface. However, the volatile components of such oils and greasesusually vaporize in a relatively short time, leaving a viscous congealedcoating. Heavy grease has been used in the past to protect the bore ofthe barrel for relatively long periods of time when the gun is not inuse. However, the use of heavy grease constitutes a messy and arduousoperation, since the grease must be completely removed before thefirearm can be re-used. The presence of moisture, as accumulated by theresidual oil, associates with the sulphurous compounds therein to formsulphuric acid which will corrode the bore.

Desiccating cartridges have been provided in the prior art for insertioninto the barrel of the firearm, and these cartridges, for the most part,absorb the moisture in the barrel in an attempt to reduce rust and otherforms of corrosion caused by moisture. The present invention isconcerned with an improved construction for such a cartridge which usesmolecular sieve adsorption materials to assure complete moistureelimination in the barrel. Cartridges incorporating the concepts of theinvention are effective for extremely long periods, even in excess of ayear, in performing their desiccating function. Inasmuch as this is abreach loading device there cannot exist the danger of a desiccant unitwithin the bore simultaneously with a live cartridge.

Bore corrosion in the barrel of a firearm is a progressive condition ifallowed to exist, for, when microscopic oxidation of the bore surfacetakes place, it cannot be eradicated and, as time goes on, it becomesmore widespread and deep seated. As atmospheric pressure varies thebarrel breathes to reach equilibrium between the internal and externalpressure thus causing the intrusion of more moisture into the bore.Under hunting conditions, for example, following the use of the gun byday, the changes in temperature at night will normally cause thecondensation of moisture on the bore surface within the gun barrel.

The cartridge of the present invention is extremely advantageous sinceit can be inserted into the firing chamber of the firearm at any timefollowing the use of the firearm; and it is effective eithercontinuously over long periods of time when the firearm is not in use,or intermittently, since it can conveniently be removed from the firearmwhenever the firearm is to be used.

The desiccating cartridge of the invention provides an instant andcontinuous getter for all latent moisture in the atmosphere within thebore of the barrel of the firearm. The cartridge is effective, asmentioned above, up to periods in excess of a year to de-moisturizelubricant oils normally used to protect the surface of the bore, or tode-moisturize the bore surface itself. The cartridge of the inventionincludes molecular sieve pellets which may be formed, for example, ofsodium aluminol silicate, or other appropriate substance, to adsorbmoisture and volatile hydrocarbons from the atmosphere in the bore. Whenadsorbed, the moisture and other gases and liquids, cannot be releasedfrom the molecular sieve except under high heat conditions.

This is a distinct advantage over the usual absorbent type ofdesiccants, which act merely as sponges, and which have a tendency torelease moisture back into the bore atmosphere after saturationconditions have been reached.

The desiccant cartridge of the invention, in the embodiment to bedescribed, is transparent, and moistureindicating pellets, for example,may be formed of metallic chlorides which are blue when dry, and whichturn buff as the adsorbed content increases to of its total capacity.The moisture indicating pellets alert the user when a new cartridgeshould be inserted.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary representationof a firearm, partly in section, and showing the desiccant cartridge ofthe invention in place in the firearm to perform its desiccatingfunction;

FIG. 2 is a side view of a cartridge forming an embodiment of theinvention;

FIG. 3 is an end view taken along the line 33;

FIG. 4 is an end view taken along the line 44; and

FIG. 5 is a view, like FIG. 2, of a slightly modified cartridge.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The cartridge of theinvention includes a hollow shell case 10 formed, for example, ofappropriate transparent plastic material, such as Lexan. A cap base 12is inserted into one end of the shell case 10, the cap base 12 beingformed of an appropriate impervious plastic material such as Delrin, ora suitable metal such as aluminum or brass. The transparent shell case10 is received in a friction fit over the end of the cap 12. The portionof the cap base 12 extending into the hollow shell case 10 is hollow, sothat the capacity of the interior of the shell case is optimized. A plug14 of high density plastic material, such as high density polyethylene,is formed in the cap 12 in position to receive the firing pin of afirearm when the cartridge is in the firing chamber of the firearm, soas to protect the firing pin from damage, acting as a shock absorber orbuffer.

An annular collar 16 is formed on the other end of the hollow shell case10, and it supports a perforated metal member 18 which, in turn, servesas a support for a porous end wall formed, for example, of filter fiber.As an alternative, and as shown in FIG. 5, the collar 16 may beeliminated, and two perforated metal members 18a and 18b may besupported in a countersunk recess at the end of the case 10, with thefilter fiber interposed therebetween.

The cap base in the embodiment of FIG. 5 fits over the end of the case10 and it has a hollow interior to increase the capacity of thecartridge.

A plug 19 of impervious plastic material, such as polyethylene isprovided. The plug has a hollow end portion 19a which is dimensioned tofit over the collar 16 in friction fit with the collar. The plug forms aclosure for the cartridge when it is not in use, in order to preservethe integrity of the desiccating material contained in the shell case10. The other end of the plug 19 is dimensioned to fit into the muzzleof a fireann, such as the firearm 20 in FIG. 1, to form a closure forthe bore of the barrel when the cartridge 10 is in place gin place inthe muzzle of the firearm to serve as an indicator that the plug is inplace, and to obviate any possibility of the firearm being'fired beforethe plug is removed.

As mentioned above, the desiccant material in the shell case may be inthe form of molecular sieve pellets. Such pellets are presently on themarket and, for example, may be synthetically produced crystalline metalaluminol-silicates which are activated for adsorption byremoving theirwater of hydration. Because little or no change in structure occursduring the hydration process, unusually highly porous adsorbents areformed that have a strong affinity for water and certain other gases andliquids. In addition, indicator pellets may be interspersed in thehollow shell case 10 to indicate the moisture adsorption by themolecular sieve pellets. The indicator pellets may be formed, forexample, of metallic chlorides and they are blue when dry, but turn buffas the adsorbed moisture content increases to a saturated condition.

The invention provides, therefore, a simple cartridge that may be easilyinserted into the firing chamber of a firearm whenever the firearm isnot in use, and which has a plug portion which normally serves as animpervious cap for the cartridge when not in use, but which also servesas a closure for the muzzle of the firearm when the cartridge isinserted into the firing chamber. The combination of the inventionoperates effectively to maintain the bore of the barrel of the firearmin a completely dry condition, so as to prevent any corrosion, or otheradverse effects on the surface of the bore due to moisture.

It will be appreciated that while a particular embodiment has been shownand described, modifications may be made. The following claims areintended to cover the modifications which come within the spirit andscope of the invention.

What is claimed:

1. A desiccant cartridge for use in a firearm, said firearm having afiring chambena firing pin, a muzzle, and a barrel having a boretherein, said cartridge being in sertable into the firing chamber of thefirearm, said cartridge including: a hollow shell case having a porousforward wall; a quantity of molecular sieve adsorbent material containedin said hollow shell case; and a removable impervious plug having ahollow end portion dimensioned to extend coaxially over the forward endof said shell case in friction fit therewith, and having a closed endportion dimensioned to be inserted into the muzzle of the firearm as aclosure for the bore of the barrel thereof.

2. The cartridge defined in claim 1, in which said molecular sieveadsorbent material is in the form of pellets.

3. The cartridge defined in claim 1, in which said shell case is formedof transparent material, and which includes a quantity of moistureindicating pellets contained in the case interspersed with saidmolecular sieve material.

4. The cartridge defined in claim 1, and which includes a cap basemounted on the rear end of said shell case, and a buffering pad of highdensity plastic material mounted on said cap for receiving the firingpin of the firearm.

5. The cartridge defined in claim 1, and which includes a ribbon mountedin the plug to extend out of the end thereof when the plug is insertedinto the muz-

1. A desiccant cartridge for use in a firearm, said firearm having afiring chamber, a firing pin, a muzzle, and a barrel having a boretherein, said cartridge being insertable into the firing chamber of thefirearm, said cartridge including: a hollow shell case having a porousforward wall; a quantity of molecular sieve adsorbent material containedin said hollow shell case; and a removable impervious plug having ahollow end portion dimensioned to extend coaxially over the forward endof said shell case in friction fit therewith, and having a closed endportion dimensioned to be inserted into the muzzle of the firearm as aclosure for the bore of the barrel thereof.
 2. The cartridge defined inclaim 1, in which said molecular sieve adsorbent material is in the formof pellets.
 3. The cartridge defined in claim 1, in which said shellcase is formed of transparent material, and which includes a quantity ofmoisture indicating pellets contained in the case interspersed with saidmolecular sieve material.
 4. The cartridge defined in claim 1, and whichincludes a cap base mounted on the rear end of said shell case, and abuffering pad of high density plastic material mounted on said cap forreceiving the firing pin of the firearm.
 5. The cartridge defined inclaim 1, and which includes a ribbon mounted in the plug to extend outof the end thereof when the plug is inserted into the muzzle of thefirearm.